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Tsagourias, N., Buchan, R. Automatic Cyber Defence and the Laws of War. German Yearbook of International Law, 60(1), 203-237.
Tsagourias, Nicholas and Buchan, Russell "Automatic Cyber Defence and the Laws of War" German Yearbook of International Law 60.1, , 203-237.
Tsagourias, Nicholas/Buchan, Russell: Automatic Cyber Defence and the Laws of War, in: German Yearbook of International Law, vol. 60, iss. 1, 203-237, [online]


Automatic Cyber Defence and the Laws of War

Tsagourias, Nicholas | Buchan, Russell

German Yearbook of International Law, Vol. 60 (2018), Iss. 1 : pp. 203–237

1 Citations (CrossRef)

Additional Information

Article Details


Author Details

Nicholas Tsagourias, Professor of International Law, University of Sheffield, United Kingdom (UK).

Russell Buchan, Senior Lecturer in Law, University of Sheffield, UK.

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Automatic cyber defence describes computer operations to neutralise a cyber attack. Once a system detects that it is under cyber attack, it automatically launches offensive cyber operations that pursue the attacker back to its own network with the objective of rescuing stolen data or disabling or destroying the computer hardware and software that is responsible for hosting and distributing the attacking code. The aim of this article is to examine the legality of automatic cyber defence under the law regulating the use of force in international law (jus ad bellum) and under international humanitarian law (jus in bello). Thus, the first part of this article examines automatic cyber defence in the context of the jus ad bellum by considering the legal requirements of an armed attack, necessity, and proportionality. In the second part, it examines the jus in bello aspects of automatic cyber defence and, in particular, whether it triggers an international or a non-international armed conflict and, if so, whether it can comply with the principles of distinction and proportionality.

Table of Contents

Section Title Page Action Price
Nicholas Tsagourias / Russell Buchan: Automatic Cyber Defence and the Laws of War 1
I. Introduction 1
II. Automatic Cyber Defence and Jus ad Bellum 5
A. Armed Attack 5
B. Necessity 1
C. Proportionality 1
III. Automatic Cyber Defence and Jus in Bello 1
A. Automatic Cyber Defence and Armed Conflict 1
1. Automatic Cyber Defence and IACs 1
2. Automatic Cyber Defence and NIACs 2
3. Automatic Cyber Defence and Challenges to the Classification of Armed Conflict 2
B. The Principle of Distinction 2
C. The Principle of Proportionality 3
IV. Conclusion 3